Evolution Unit 4 Bio

Convergent Evolution

Two or more distinct species share traits NOT due to a common ancestor.

Example of Convergent Evolution

Birds and dragonflies and bats both have wings but do not share a common ancestor.

Why Convergent Evolution Happens

Similar traits are usually evolved by similar habitats, niches, environmental pressures and natural selection.

Significance of Convergent Evolution

Convergent evolution can be used as proof to Darwin's theory. Adds to biodiversity.

Divergent Evolution

The accumulation of differences between organisms that can lead to the development of new species.

Example of Divergent Evolution

Wolves evolving into dogs.

Why Divergent Evolution Happens

Geographical difficulties, including isolation, leading a species to evolve down different paths.

Factors in Divergent Evolution

Selective breeding and natural selection because of environmental pressures.

Significance of Divergent Evolution

Adds to biodiversity by adding new breeds of animals.

Divergent Evolution

Adaptation to new environments.

Fossils

Remains of species ancestral to modern species.

Evidence for Evolution

Suggest that new species evolved from and replaced previous species.

Comparative Anatomy

Gives evidence for descent with modification.

Homologous Structures

Structures that have the same ancestral origin despite current appearance/function.

Vestigial Structures

Functionless structures inherited from ancient ancestors.

Analogous Structures

features in different species that have similar functions but evolved independently, meaning they don't share a common evolutionary origins

Embryology

Shows common ancestry among vertebrates. The branch of biology and medicine concerned with the study of embryos and their development.

Karl von Baer

Observed that all vertebrate embryos resemble one another.

Biochemistry

Biochemical similarities show relatedness among organisms.

Homologous Molecules

Molecular similarities among organisms.

Carbon-based Organisms

All organisms on Earth are carbon based.

DNA

All cells have DNA, RNA, ribosomes, and the same 20 amino acids.

ATP

Cellular energy carrier in eukaryotic cells.

Genetics

DNA sequencing shows similarities in nucleotide sequence.

Cytochrome C

Gene for cytochrome C is found in all plants and animals with the same function. In mitochondria in charge of ATP production

Molecular Homology

Sequencing DNA to find similarities among organisms.

Tail and Gill Slits

Embryos of vertebrates share many similarities such as tail and gill slits.

Fundamental Similarities

All cells share fundamental similarities including DNA, RNA, ribosomes.

20 Amino Acids

All organisms use around 20 amino acids.

Fossils

Provide evidence of evolutionary change over time.

Natural Selection

The process where organisms with traits better suited to their environments tend to live longer and reproduce more successfully.

Postulate 1

Individuals in a population vary: Different sizes, eye colors, skin colors, fur color, etc.

Postulate 2

Traits are passed from parent to child.

Postulate 3

You need to live to reproduce. Must have more organisms born than ones that reproduce.

Postulate 4

Survivability is not based on chance; reproductive success depends on an individual's characteristic.

Descent with modification

The concept that organisms with more advantageous traits have better odds of surviving and reproducing.

Jean-Baptiste Lamarck

An early proponent of evolution who thought that evolution had 2 main parts: the complexifying force and the adaptive force.

Complexifying force

The idea that organisms get more complex structure over time.

Adaptive force

The idea that organisms will adapt to their environments and improve towards perfection in their environment.

Gregor Mendel

Discovered genetic heredity and laid the mathematical foundation for the science of heredity.

Recessive inheritance

A form of genetic inheritance discovered by Gregor Mendel.

Erasmus Darwin

Grandfather of Charles Darwin who discovered that all warm-blooded animals came from the same form and anticipated the idea of natural selection.

Charles Darwin

Came up with the theory of natural selection, stating that all species of organisms arise and develop through natural selection.

Better-adapted organisms

Organisms that survive and produce offspring with the same genetic traits, allowing them to survive.

Cytochrome c

A gene found in mostly all animals, plants, fungi, and protists.